The present invention relates generally to ice makers.
Ice makers, particularly those used in homes and small businesses are well known and employ a refrigeration system to chill an ice forming surface below the freezing temperature of water. Such refrigeration systems typically include a compressor, an evaporator and a condenser all connected by refrigerant lines. The ice forming surface is thermally connected to the evaporator and is chilled to a temperature below the freezing temperature of water, then a supply of water is dispensed onto this surface and allowed to freeze. In some systems, the water is dispensed onto the surface and all of the dispensed water is held there until it has frozen into ice. In other systems, the water flows over the chilled surface and some turns to ice and the remainder is collected and recirculated. Such a system is disclosed in U.S. Pat. No. 4,009,595 which was assigned to the assignee hereof, and which is incorporated herein by reference.
A problem that develops with ice makers is that minerals in the water, and particularly calcium, form deposits on the ice forming surface, decreasing the thermal transfer effectiveness of the ice forming surface, thereby decreasing the effectiveness and energy efficiency of the ice maker, as well as causing the ice to be retained on the ice forming surface rather than being released from that surface during harvesting of the formed ice. This requires the ice forming surface to be cleaned on a regular basis to remove these deposits.
Also, the recirculation pump which is used to supply water to the ice forming surface is subject to corrosion from the minerals in the water being recirculated. As the water freezes onto the ice forming surface, the remaining recirculating water become rich in minerals, increasing the problem. It is known, for example as disclosed in U.S. Pat. No. 4,785,641, to operate a discharge pump for a predetermined period of time to flush remaining water from the reservoir prior to each ice making cycle and to allow the ice forming surface to cool to below freezing temperature before water is circulated over the ice forming surface.
U.S. Pat. No. 6,000,228 discloses an ice making apparatus in which water is supplied through a water valve for a predetermined time period. Water is circulated by a pump from a water sump to an ice forming surface for a second predetermined time period. The sump is drained via gravity through a drain valve for a third predetermined time period.
It would be an improvement in the art if an ice making apparatus and method were provided wherein less water is used during the process of forming a given batch of ice and fresh water is provided for each new batch of ice.